Rope Tornado Videos (do you have one?)

[Robert Edmonds]

Hi all,

This is a thread to request rope tornado videos. This is not for a commercial interest simply a little curiosity, so if you don’t mind sharing that’d be great!

Why?

If you read a recent post of mine (http://stormtrack.org/forum/showthread.php?t=25466) I recently (last weekend) made another little vortex code. Anyhow, I was slightly curious if the model could reproduce any thing observed in tornadoes. So I went searching around and came across:
http://www.liveleak.com/view?i=eed_1224090414
(BTW don’t know who to give credit to for video)

After aligning some frames the best I could tell is the loop (in the gustnado/tornado) appears to be moving upward slightly (see image below). Since the model I made assumes that the frame is moving with the overall flow (u(inf),v(inf)), I also aligned the base of vortex.

So I went ahead and attempted to plug in a curve into the model that had some similar characteristics as the in the video above. Anyhow this is what I get:

The [first] loop does appear to move upward, and inward. (Note needed to add more loops for the model to work)

So I want to see if this model could reproduce the motions of other rope tornadoes. Thus if you have any that’d be great! Different shapes should produce different motions so I'm curious if the model can reproduce the motions or not. The longer the rope probably the better in this case.

 

[Eric Sipes]

This is the best one we have (that I can think of). It's several tornadoes in Floyd Co. TX on 3/28/07. The last of which transitions from pencil to rope form several times before dissappating.

 

[Wesley Luginbyhl]

The rope out begins 7 minutes into my video. The rope out is timelapsed because it was a very long rope out.

 

[AndyGabrielson]

The entire life of the first tornado was basically a rope....

http://www.youtube.com/watch?v=OWNlQuC42AA

near Schell City/Harwood, MO June 10 - 2009

 

[Scott Hammel]

Here's my video from August 16th Deer Trail/Brush, CO. Land spouts and rope tornadoes are in there...

http://www.youtube.com/watch?v=_SgYIwS_hPs

 

[David Drummond]

There is a pretty cool rope out on one of the tornadoes on my video here. Tornado starts about about :30 in to the video and begins rope stage about 2:20.



Here is another from just west of OKC this year during the outbreak. This thing was a rope practically it's whole life.

 

[Robert Edmonds]

Thanks for the links to the videos, I've been enjoying them. Keep them coming, there's probably some stuff I could use in here already. As usual hard to make out depth. Some beautiful ropes you guys.

 

[Tom Dulong]

July 18, 1986 Minneapolis Tornado

This is an oldie but a goody. It was caught by Minneapolis KARE TV 11's News Copter on 18 July of 1986. Several phases of a helix can be seen in the tornadic circulation beginning about 2 minutes into this video.

http://www.youtube.com/watch?v=LclcYJO6qDE&feature=related

This seems to behave like your simulation in the original post.

 

[Jeff Snyder]

I have the roping of the 3/8/10 tornado near Hammon, OK. See near the 7:55 mark in http://www.youtube.com/watch?v=o8bdv2k-CYo ... The 3/28/07 Brice, TX, tornado had a nice rope-out stage as well, but I can't find my video online from that right now.

 

[Robert Edmonds]

Thanks again everyone!

The link Tom provided, is what I'm starting with (wow). If others want to provide more links I'd be more than happy to look at them.

 

[Jesse Risley]

I'm going to throw in my video from the Lindon, CO tornado on June 10, 2010. I made the video into a time lapse, so admittedly the first minute or so is choppy, but if you start viewing right at 2:05 and continue viewing till the end of the video, you'll see a rather impressive rope out phase of that final tornado.

J

 

[Robert Edmonds]

So figured I would give a little update. I hope to reproduce some more features as seen in Tom’s link. However, I haven’t been able too. Despite that, I thought I might share what was produced. So I thought a helix increasing in amplitude might mimic some of the characteristics of the tornado, so that’s what I plugged into the model. Below is what I get.


Still interesting in the behavior despite not matching what I see in the video Tom linked to, and I’ll try to explain what I think is going on (in the model) below.

So the increased curvature causes the smaller loops (red above), to catch up to the larger loops above (orange). So as they do so, the line straightens at the base.

Since the ‘string’ must remain the same length (i.e. conserve vorticity), this creates an additional curl inside the helix (red). [there’s gotta be some better lingo]

Anyhow, that’s what I have so far… probably will be able to play some more next weekend.

Edit: At least the helix moves upward... Anyone have any ropes where the helix rotates clockwise with height but are cyclonic?